One prior art impact tool has a first part, a second part, and a body. The first part has an engaging portion which has a penetrating through hole. The second part is made of a soft material which has an engaging hole for receiving the engaging portion of the first part. A front end of the body has an operation portion. The body can be engaged to a recess of the first part. The lower end of the body and the operation portion expose out of the first part. Thereby when the second part is held, since the second part is made of soft material and an operation portion resists against a work piece and a hammer collides a body, the vibration will be absorbed by an air chamber of the second part. Thereby the hand of the user will not be hurt.
However the structure of the prior impact tool is too simple and has unique function which is not suitable for current design concept of tools. The current design principle for tools requires that the tools have multiple functions so that one tool can perform several functions. Thereby a user only needs to carry one tool for several different operations. Further, the prior art impact tool has a short arm of force which is not suitable for driving a tighten engaged screwing object.